Exterior Wall Sealants, What are exterior wall sealants
Exterior wall sealants speaks to what are exterior wall sealants, why exterior wall sealants and types of exterior wall sealants.
The fact that most exterior wall systems require sealant joints, which are seams that are closed with rubber like compounds.
Systems that do not use sealants as water barriers in the face of the wall, frequently use them to seal joints in the air barrier behind the face. The role of sealant is to fill the joints between wall components, preventing the flow of air or water while still allowing reasonable dimensional tolerances for assembly and reasonable amounts of subsequent movement between the components.
Sealant joint widths are usually three eighth to three quarter inch (9 to 19 mm) but can be as small as one quarter inch (19 mm) and sometimes range up to one inch (25 mm) or more.
Sealants are often used to seal joints between panels of stone or precast concrete in a curtain wall to seal the joint beneath the shelf angle in a brick curtain wall and to seal joints between dissimilar materials. This may be noted such as where a metal and glass cladding system ends against a masonry wall.
Specially formulated sealants are use to seal between lights of glass and the frames that support them. This helps to prevent the passage of sound around the edges of interior partitions.
To apply polysulfide, a high range gunnable sealant to a joint between exposed aggregate precast concrete curtain wall panels a sealant gun is used. The operator moves the gun slowly so that a bulge of sealant is maintained just ahead of the nozzle of the sealant gun. This exerts enough pressure on the sealant so that it fully penetrates the joint.
Following application, the operator will return to smooth and compress the wet sealant into the joint with a convex tool. This is much the same procedure as when a mason tools the mortar joints between masonry units.
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